The present invention relates to a robotic welding torch. More particularly, the present invention relates to an improved robotic welding torch having easily interchangeable parts and greater functionality in addition to an improved method of assembly.
Robotic welding torches are used in arc welding environments requiring repetitious precision welding, such as mass production of automobiles or automotive parts. Arc welding robots are generally high precision, computer controlled machines containing electric servomotor drives. The welding robots use special interfaces to connect with robotic arc welding equipment. The welding robots typically use an articulating jointed arm to move the attached robotic torch assembly to the desired position. Robotic welding is often used for arc welding parts where the travel distances between welds are large. Robotic torches, such as robotic metal inert gas (MIG) torches, utilize consumable wire electrodes fed from a spool in a separate wire feeder. Also, the robotic torches require a supply of shielding gas and electric current to perform the welding tasks.
The rapid and precise welding applications for which robotic MIG welding torches are used require torch assemblies that are easily assembled and repaired. Robotic welding devices may be subject to heat and wear due to continuous operation. Ease of repair and replacement of the MIG torch can greatly affect the amount of lost production time. Further, the cost of the replacement torch or torch parts can determine the utility of a particular robotic torch design.
Some robotic torch assemblies use a one piece non-removable body tube. In this configuration the entire robotic torch must be disassembled to change the body tube if it becomes damaged or worn. Disassembly of the entire torch is often time consuming and labor intensive. Another type of body tube presently used is a removable, keyed body tube. In this configuration, the body tube can be removed without complete disassembly of the torch, but requires a specific tool to remove. A related type of removable, keyed body tube can be removed without complete disassembly of the torch and without tools, but utilizes a thumb nut that protrudes from the profile of the body of the torch. The thumb nut can break off during use because the raised profile of the nut may impact on items while the torch is moving during welding.
Robotic welding torches often incorporate a robotic arm mount to allow the welding robot to attach to the welding torch. One common configuration is a dedicated mounting diameter that is used as a mounting surface and is an integral part of the torch. Because different welding robots may have interfaces that require different robotic torch diameters, this type of design requires that a welder use separate dedicated robotic welding torches every time each different welding robot is used. A user must then possess and maintain several different robotic welding torches. Some robotic mounts have a changeable diameter, but require complete disassembly of the robotic torch, because the body of the torch is the mounting surface.
Another approach to attaching a robotic welding torch to a welding robot is through the use of a combination arm and coupler. One configuration available is a keyed aluminum arm that is a separate component from the torch. The arm is sometimes manufactured from one piece of aluminum. Several fasteners, such as screws, are typically utilized to retain the robotic torch to a collision sensor on a welding robot. The solid aluminum arms are often heavy, costly, and do not offer electrical feedback protection or collision protection. Other robotic mounting arms use two or more pieces of aluminum where the separate pieces are connected with a screw or nut and bolt, as well as to the collision sensor of the welding robot. The multi-piece design of is type of mounting arm may shift from a desired position, if bumped or jarred, causing damage to the robotic torch or the robot itself during operation.
Accordingly, there is a need for a robotic welding torch assembly having easily removable and attachable parts. A replaceable robotic mount is needed that does not require disassembly of the entire robotic torch and that facilitates changing between welding robots thereby reducing the need to stock multiple robotic torches for different welding robots. A low profile fastening mechanism that reduces accidental loosening and breakage of fasteners is desirable. In addition, a lightweight, electrically insulating integrated robotic mounting arm having an accurate and repeatable mounting capability is needed.